Across
- 2. the place where all space exists
- 4. primary fuel used by stars
- 7. not quite a planet because it cannot clear debris from it's orbit
- 13. distance light travels in 1 year
- 14. billions of stars
- 15. how bright a star appears from earth
- 19. occurs after an average star runs out of hydrogen fuel
- 20. cloud of gas/dust where stars are born
- 21. diagram that plots stars according to luminosity and surface temperature
- 24. mercury, venus, earth and mars
- 25. jupiter, saturn, uranus and neptune
Down
- 1. medium sized, average star closest to Earth
- 3. galaxy without shape
- 5. galaxy with very smooth features
- 6. transfer of energy through matter and space by waves
- 8. how bright a star actually is
- 9. where the Sun is located in the Milky Way galaxy
- 10. hot,dim stars at the end of their life
- 11. takes 365 days
- 12. the unit used to measure distances in our solar system
- 16. brightness or energy from a star
- 17. equals 3.26 light years
- 18. our galaxy
- 22. causes day and night
- 23. galaxy with arms and a bulge